1. Field of the Invention
The instant disclosure relates to a manufacturing method of capacitor structure; in particular, to a manufacturing method of high capacitance capacitor structure of dynamic random access memory (DRAM).
2. Description of Related Art
Random access memory (RAM) is a form of computer data storage which includes transistors, capacitors and peripheral controlling unit. In order to increase computing performance, it is important to increase the surface area of the capacitor unit in the memory to increase the electric charge storing capacity.
The technology of integrating double sided capacitor in dynamic random access memory (DRAM) has been of increased emphasis. In order to further advance the integration of DRAM, a miniaturization process that can effectively reduce the section area per unit of capacitance and the space between two electrodes of capacitor is greatly desired. In the limited space that a modern miniaturized electric component can spare, a capacitor needs to achieve small form factor yet at the same time capable of providing adequate capacitance to remain satisfied signal intensity. Accordingly, DRAM design needs to focus on the capacitor structure and the layout closely affecting the capacitance thereof. The use of double sided capacitor, which offers higher per unit charge storing capacity, ma be helpful in the reduction of an overall height of a memory unit.
However, conventional double sided capacitor structure has a large aspect ratio of height over width for obtaining a large surface area, which makes the capacitor structurally weaker and unstable, which leads to the increased risk of collapse. In addition, the manufacturing method of the above-mentioned capacitor generally requires a complex process flow, wherein the photolithography process requires a high-precision in alignment. As a result, the conventional manufacturing process flow may be inadequate in achieving desired production and yield rate.
To address the above issues, the inventors strive via industrial experience and academic research to present the instant disclosure, which can effectively improve the limitations described above.